Exploring Thermophilic Cellulolytic Enzyme Production Potential of Aspergillus fumigatus by the Solid-State Fermentation of Wheat Straw
| Autor: | M. Javaid Asad, Muhammad Gulfraz, Nazia Mehboob, Raja Tahir Mahmood, Tariq Mukhtar, Muhammad Asgher |
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| Rok vydání: | 2014 |
| Předmět: |
Ammonium sulfate
Hot Temperature Size-exclusion chromatography Bioengineering Cellulase Applied Microbiology and Biotechnology Biochemistry Fungal Proteins Industrial Microbiology chemistry.chemical_compound Enzyme Stability Food science Molecular Biology Triticum Ammonium sulfate precipitation Plant Stems biology Aspergillus fumigatus Fructose General Medicine Culture Media chemistry Solid-state fermentation Fermentation Urea biology.protein Biotechnology |
| Zdroj: | Applied Biochemistry and Biotechnology. 172:3646-3655 |
| ISSN: | 1559-0291 0273-2289 |
| DOI: | 10.1007/s12010-014-0796-3 |
| Popis: | Cellulases can be used for biofuel production to decrease the fuel crises in the world. Microorganisms cultured on lignocellulosic wastes can be used for the production of cellulolytic enzymes at large scale. In the current study, cellulolytic enzyme production potential of Aspergillus fumigatus was explored and optimized by employing various cultural and nutritional parameters. Maximum endoglucanase production was observed after 72 h at 55 °C, pH 5.5, and 70 % moisture level. Addition of 0.3 % of fructose, peptone, and Tween-80 further enhanced the production of endoglucanase. Maximum purification was achieved with 40 % ammonium sulfate, and it was purified 2.63-fold by gel filtration chromatography. Endoglucanase has 55 °C optimum temperature, 4.8 optimum pH, 3.97 mM K m, and 8.53 μM/mL/min V max. Maximum exoglucanase production was observed at 55 °C after 72 h, at pH 5.5, and 70 % moisture level. Further addition of 0.3 % of each of fructose, peptone, and Tween-80 enhances the secretion of endoglucanase. It was purified 3.30-fold in the presence of 40 % ammonium sulfate followed by gel filtration chromatography. Its optimum temperature was 55 °C, optimum pH was 4.8, 4.34 mM K m, and 7.29 μM/mL/min V max. In the case of β-glucosidase, maximum activity was observed after 72 h at 55 °C, pH 5.5, and 70 % moisture level. The presence of 0.3 % of fructose, peptone, and Tween-80 in media has beneficial impact on β-glucosidase production. A 4.36-fold purification was achieved by 40 % ammonium sulfate precipitation and gel filtration chromatography. Optimum temperature of β-glucosidase was 55 °C, optimum pH was 4.8, K m was 4.92 mM, and V max 6.75 μM/mL/min. It was also observed that fructose is better than glucose, and peptone is better than urea for the growth of A. fumigatus. The K m and V max values indicated that endoglucanase, exoglucanase, and β-glucosidase have good affinity for their substrates. |
| Databáze: | OpenAIRE |
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